3.12 cannot be supported due to pathtools dependency

[mpitblado]

Due to the requirement of pathtools, we have found that this cannot run using Python 3.12. See gorakhargosh/pathtools#13. This may prompt a change in text within the README to mention this, so that users know to start the virtual environment with python 3.11 or lower.

I am not sure the status of the pathtools repository, it hasn't had a commit in 8 years.

[Gene-Weaver]

In commit 216c5b1 I removed some unused packages that ended up in the requirements.txt including pathtools. I have not validated Python 3.12, but it might play nicely now. Anyway, I added to the readme that beyond 3.11 may not be stable since some of LeafMachine2 relies on older versions of some packages, especially PyTorch (which will work with PyTorch 2.X+ if you play around with updating some dependencies).